Furnace.



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FURNACE. AEPLIOATION FILED JAN. 23, 1909.

984,910. I Pate n ted Feb.21, 1911.

4 SHEETS-SHEET 1.

J. HARRINGTON.-

vFURIHGF. APPLIOATION FILED JAIL-23,1909.

Patented Feb. 21, 1911.

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FURNACE.

'APPLIOATION FILED JAN. 23, 1909. 984,91 0. Patented Feb. 21, 1911.

4 SHEETS-SHEET 3.

Iii If iii/if J. HARRINGTON.

FURNACE.

APPLICATION FILED JAN. 23, 1909.

Patented Feb.21, 1911.

4 SHEETS-SHEET 4.

la zlzffarm 21 01% (52/115,111. by -KS JOSEPH HARRINGTON, OF RIVERSIDE, ILLINOIS.

FURNACE.

To all whom it may concern:

Be it known that I, JOSEPH HARRINGTON, a citizen of the United States, and a resident of Riverside, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Furnaces; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

This invention relates to improvements in furnace grates of that class in which the fuel supplied to the front of the grate is caused to travel or move inwardly thereon during the progress of combustion, and more especially to that kind of such grates in which the supporting surface thereof consists of two sets of grate-bars extending from front to rear of the furnace and the bars of one set arranged in alternation with the bars of the other set, and in which the bars of at least one of said sets are given rising and falling and endwise movement to eflect the advance of the fuel resting on the grate.

The invention consists in the matters hereinafter described and pointed out in the appended claims.

In the accompanying drawings illustrating my invention :Figure 1 is a view in central, vertical, longitudinal section of a furnace equipped with a grate embodying my invention. Fig. 2 is a view in elevation of the front of the furnace, showing onehalf of the same, certain parts of the gratebar actuating devices being shown in section. Fig. 3 is an enlarged, detail, vertical, longitudinal section, showing the actuating devices for the grate-bars and adjacent parts. Fig. 4 is a detail view of one end of the supporting girder for the front ends of the grate-bars. Fig. 5 is an enlarged detail plan view of the forward ends of the grate-bars, the actuating devices therefor, and adjacent parts. Fig. 6 is a like enlarged detail plan view of the rear or inner ends of the gratebars and means for supporting the same. Fig. 7 is a detail section taken upon line 77 of Fig. 5. Fig. 8 is a detail section taken upon line 8-8 of Fig. 6. Fig. 9 is a detail section, corresponding with Fig. 3, showing a modified construction in which the grate-bars of one set are stationary.

Specification of Letters Patent.

Application filed January 23, 1909.

Patented Feb. 21, 1911. Serial No. 473,892.

Fig. 10 is a detail section showing the supports for the lower ends of the grate-bars shown in Fig. '9. Fig. 11 is a detail section taken upon line 11-11 of Fig. 10. Fi 12 is a detail section showing a modified orm of the means for supporting the lower ends of the grate-barswhen all of the same are movable.

As shown in said drawings, 5 indicates the front wall of a furnace, provided with a fuel-feed opening 6, and with a hopper 7 through which fuel is fed to said opening.

8 indicates a horizontal plate forming the bottom surface of the feed opening 6 and over which the fuel is fed to the forward end of the grate.

9 indicates a transverse supporting beam or girder, located at the rear end of the grate, which extends transversely between the side walls of the furnace and by which the rear end of the grate is supported.

As shown in Figs. 1 to 8,10 and 11 indicate two sets of grate-bars, which extend from front to rear of the furnace, the bars 10, 10 constituting one set being arranged in alternation with the bars 11, 11 constituting the other set. The grate-bars are shown in the drawings as being inclined downwardly at a slight inclination from the front toward the rear of the furnace, but said grate-bars need not be so inclined, or they may be inclined at a greater or less inclination than that shown.

Devices are provided at the forward ends of the grate-bars for giving rising and falling and also endwise movement to the forward of the end bars of each set. The rear ends of the grate-bars of both sets rest or are supported upon the girder 9 with their upper surfaces in the same plane, and the said rear ends of the bars have backward and forward movement relatively to said girder. The devices for actuating the grate-bars are constructed'as follows: 12 indicates a rotative shaft which extends horizontally across the front of the furnace outside of the front wall 5 thereof. Said shaft is mounted at its ends in bearings on upright frame-plates 13, 13 located at opposite sides of the front of the furnace. Rotative movement is given to said shaft 12 through the medium of a counter-shaft 14 located at the left hand side of the furnace (Fig. 2), provided with a gear-wheel 15 which intermeshes with a gear-wheel 16 on the adjacent end of said 32, 32, littlespace is left for the entrance of air to the furnace between the front ends of the grate-bars and said wall.

In order to permit the several grate-bars to be removed from the furnace when desired for repairs or replacement, without disturbing the yoke members 22 and 23, a detachable joint is formed between the forward end of each grate-bar and its associated yoke member. Such joint, as shown, is formed by means of a projection 33, of dove-tail shape, which is adapted to fit into a vertically extending socket in the adjacent end of the yoke member, said projections 33 being downwardly tapered at its side margins, as seen in Fig. 7 in order to insure a close fit between the end of the grate-bar and yoke member. The said gratebars 10 and 11 are shown as made of inverted U-form in cross-section, consisting of a horizontal top plate provided with depending marginal flanges; the top plate being provided with slots or openings for the admission of air to the fuel.

Theyoke members 22 and 23 are located at such distance below the feed plate 8 as to give room for the rising and falling movement of said yoke members, and in order to prevent the entrance of air to the part of the furnace above the grate, features of construction are provided as follows: 35,

indicate swinging gates or closure members which are supported by means of arms 36, 36 which are pivotally connected with the plate 8 at points forward of the gates. Said gates rest upon and have rising and falling movement with the yoke pieces over which they are severally located. Each of said gates is equal in width to the yoke member below it, and the several closure members are arranged with their side edges in sliding contact with each other. Each gate, moreover, is adapted for sliding contact at its side edges with the two yoke members at opposite sides thereof in the rising and falling movements of said yoke members. The said gates, by resting at their lower edges on the yoke 'members, prevent particles of coal from being carried outwardly upon or with said yoke members, acting to scrape such particles from the yoke mei'nbers as the latter are retracted. To secure the proper scraping action, the faces of the said gates are made of concave form, as shown. In connection with the gates thus made, the fuel plate 8 has upon its rear edge a depending flange 37 which overhangs the gate members and is curved on its inner face to correspond wit-h the arc in which the gatesswing. The upper edges of the gates are arranged closely adjacent to said flange, so that close joints are maintained between the gate flange and the several gate members in all positions of the latter. In the particular construction shown in the drawings, the arms 36, 36 of the gates are pivotally connected with the fuel plate 8, as follows: On the under surface of the said plate 8 is formed a depending rib 38 having at its lower edge a horizontal flange which extends inwardly or toward the furnace and is provided with a rounded rib 39 which forms a pivotal support for the several gates. The arms 36 of each gate has at its outer end a bearing portion or socket- 40 which fits over the rounded rib 39 and, while holding the gate from endwise movement, permits the same to freely rise and fall. As each of said plates is practically in contact with its associated yoke member at its lower edge, with the flange 37 at its upper edge and with the gates and yoke members at opposite sides of the same, the several gates together serve to entirely prevent at all times the inward passage of air between the plate 8 and the forward ends of the grate-bars.

Means for supporting the rear or inner ends of the grate-bars 10 and 11 upon the supporting girder 9, in such manner as to permit each bar to be moved freely backward and forward and also to permit vertical swinging movement of the forward ends of the bars, are provided as follows: Said beam 9 is provided at its top with transverse tracks or ways 41, 41 on which rest rollers 42, 42, by which the rear ends of said grate-bars are inovably sustained; said rollers being adapted for rolling contact both with said tracks or ways and the under surfaces of the bars. The said tracks or ways 41, 41 have horizontal top or hearing surfaces, while the grate-bars are provided with downwardly facing bearing surfaces at their rear ends, which are also horizontal, so that the rear ends of both sets of grate-bars move horizontally, or have no rising or falling movement, as said bars are moved backward and forward and are raised and lowered at their forward ends by the actuating devices hereinbefore described. The said tracks or ways are shown as arranged in pairs, one pair for each grate-bar, and the rollers are approximately equal in length to the width of the bars, and rest at their ends on the two tracks of each pair. The bearing surfaces of the grate-bars are formed on the depending flanges of the bars and engage the end portions of the rollers. In order to prevent the accumulation of ashes between said rollers 42 and the tracks or ways 41, the beam 9 is provided with forward and rear web-members 43 and 44, and said tracks or ways are formed by ribs which extend between said web-members and which are of tapered or wedge-shape at their upper margins; open spaces being left between said ribs through which the ashes may fall. The rear web-member 44 is shown as being inclined downwardly and forwardly so as to present an inclined surface to direct forwardly the ashes that may fall thereon while the web-member 43 terminates at its lower edge above the lower part of said web-member 44 so as to leave a slot or opening through which the ashes may pass from the web-member 44. Some of said ribs are extended downwardly so as to afford transverse connecting members between the webs 43 and 44. Said ribs 41, 41 are provided at their forward and rear ends with stop projections 45 and 46 acting to limit the movement of the rollers thereon. In order to prevent endwise shifting movement of the rollers on said tracks or ways,

, the rollers are provided with grooves near their ends to receive tapered or angular upper edges of the tracks. In connection with the rollers thus constructed, the marginal flanges on the grate-bars are provided with tapered or angular edges adapted to fit within said grooves in the rollers.

In a construction such as described, wherein the rear ends of the grate-bars have no vertical movement, while the forward ends thereof are given both endwise and rising and falling movements, there will be substantially no fuel-feeding action at the rear or inner ends of the grate-bars while there will be maximum fuel-feeding action at the forward ends thereof. An important advantage is gained from this construction, as will be understood from the following: Inasmuch as the combustion of the fuel will proceed continuously as the said fuel moves rearwardly on the grate, the fuel will be practically consumed as it reaches the rear end thereof, and the thickness of the layer of fuel on the grate will gradually decrease from the front to the rear of the grate; it being understood that burned-out fuel or clinkers and ashes alone shall be discharged from or over the rear end of the grate. It is desirable that the quantity of air passing through the grate-bars to the fuel bed should be substantially uniform throughout the area of the grate, but if the rate of feed of the fuel were the same at the rear as at the forward part of the grate, the layer of burnedout fuel, consisting mainly of clinkers and ashes, at the rear part of the grate would be so thin as to permit a larger quantity of air to pass through the fuel layer at the rear than at the forward part of the grate. In the operation of the grate made as described, the rate of rearward travel of the layer of fuel will gradually decrease from the front toward the rear part of the grate and there will be practically no movement given by the grate-bars to the part of the layer on the rear end of the grate, so that a gradual thickening or condensation of the part of the layer at said rear end of the grate will take place through the crowding or pressing of the burning fuel on the forward part of the grate against the part of the layer at the rear end thereof. In other words, by the holding back or retardation of the burnedout fuel, adjacent to the rear end of the grate, the rearwardly moving mass of fuel at the forward part of the grate will be carried or crowded against the same, so as to prevent the layer becoming so thin at the rear part of the grate as to permit the free passage of air therethrough, while the unconsumed portions of the fuel and ashes will be pushed or forced from the rear end of the grate by the pressure of the advancing layer forward of it.

Instead of making both sets of grate-bars movable, the bars of one set, such as those marked 10, 10, may be given movement by the means and in the same manner described, while the other set is stationary. A construction of this kind is shown in Figs. 9, 10 and 11, wherein the parts are made and arranged as hereinbefore described, with respect to the set of bars 10, 10, and are lettered in the drawings to correspond with the like parts in the Figs. 1 to 8. In this instance, intermediate stationary bars 47, 47 are employed in connection with the set of movable bars 10, 10, said stationary bars being secured at their forward ends by bolts or otherwise to a girder 48 which extends across the front of the furnace at the rear or inside of the beam 26. The rear ends of said stationary bars, in this instance, rest in seats 49 formed on the girder 9 and elevated above the roller-supporting tracks 41, 41, which sustain the supporting rollers of the movable bars. When one of the sets of gratebars is stationary and the other movable, it will be manifest that the layer of fuel will rest upon the stationary bars when the movable set of bars is depressed and is moved backwardly, and said layer will be lifted and sustained by the said movable bars when the latter are moving forwardly and have been lifted above the stationary bars.

It is manifestly unnecessary, so far as the operation of the grate-bar actuating devices is concerned, that the rear ends of the bars should be supported upon the rollers, as shown, and a support for the said rear ends of the grate-bars may be employed, such as is shown in Fig. 12, wherein horizontal downwardly facing surfaces formed on the rear ends of said bars rest or bear upon an upwardly rounded or convex top surface 50 formed on a supporting girder 51.

It will be understood that the actuating devices for giving rising and falling, and backward and forward endwise movement to the grate-bars, made as'hereinbefore described, may be employed as well in connection with grate-bars which have rising and falling movement at both their forward and rear ends, as in connection with grate-bars which have rising and falling movement at their forward ends only. It will also be understood that a device embodying my invention may be embodied in various forms differing from that illustrated, and I do not, therefore, desire to be limited to the specific features of construction shown, except so far as the same may be claimed in the appended claims as parts of my invention.

I claim as my invention 1. In a furnace, the combination of gratebars having endwise reciprocatory and rising and falling movement, a fuel-plate located above the forward ends of said gratebars and provided at its rear margin with a depending flange, and means for closing the space between the lower edge of said flange and the several grate-bars comprising a plurality of vertically swinging gates which are provided with forwardly extending, pivotally supported arms, and the upper margins of which are closely adjacent to said flange in all positions of said gates.

2. In a furnace, the combination of a plurality of grate-bars having endwise reciprocatory and rising and falling movement, ,afuel-plate located above the forward ends of the said grate-bars and having at its rear edge a depending flange and forward of said flange a rib provided with a rounded edge, and a plurality of vertically swinging gates located severally above the grate-bars and provided with forwardly extending arms, the upper margins of said gates being located closely adjacent said flange in all positions of said gates, and said forward extending arms having at their rear ends sockets engaging said rounded edge of the rib.

3. In a furnace, the combination of a plurality of gratebars, means acting on the forward ends of said bars to give endwise reciprocatory motion thereto, and means for sustaining the rear ends of said bars com prising a transversely arranged, horizontal girder embracing front and rear web members and aplurality of separate ribs extending between said'web members, the upper edges of which ribs form tracks or ways, and rollers interposed between said tracks or ways and the rear ends of said bars, said rollers being provided each with two grooves to engage two of the tracks or ways, and the rear ends of each of the grate-bars being provided with depending longitudinal ribs, the lower edges of which engage said grooves in the rollers.

In testimony, that I claim the foregoing as my invention I affix my signature in the presence of two witnesses, this 19th day of January A. D. 1909.

JOSEPH HARRINGTON,

WVitnesses:

T. A. MARSH, G, A. Go DnR, 

